Cloning, mapping and gene product identification of rhaT from Escherichia coli K12.
Rhamnose utilization requires the function of a specific rhamnose transport system. Rhamnose transport mutants have been isolated and characterized. The structural gene, rhaT, encoding the rhamnose permease has been cloned from Escherichia coli. rhaT has been mapped in the rha locus (87.7 min) by analysis of cotransduction with glpK and other rha markers. The precise location of the gene has been determined by complementation analysis of rhamnose transport mutants transformed with recombinant plasmids containing different fragments of the cloned region. Gene order (counterclockwise) is established as glpK . . . rhaT-rhaR-rhaS-rhaB-rhaA-rhaD. The gene product has been identified by expression of rhaT in a T7 RNA polymerase/promoter system. This 23 kDa protein has been assigned to the rhaT product and has been shown to be located in the cell membrane.
Baldomá
L
L
Department of Biochemistry, Faculty of Pharmacy, University of Barcelona, Spain.
Badía
J
J
Sweet
G
G
Aguilar
J
J
D001692:Biological Transport; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D007700:Kinetics; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D015183:Restriction Mapping; D012210:Rhamnose / Q000378:metabolism*; D027981:Symporters; D014161:Transduction, Genetic; D014169:Transformation, Bacterial
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C067370:RhaT protein, E coli; D027981:Symporters; D012210:Rhamnose